Machine Language Manager (MLM) is a 2KB cartridge written by Andy Guevara in 1981 for the Bally Arcade/Astrocade. It was released by The Bit Fiddlers in late 1981/early 1982.
This video overview summarizes the Machine Language Manager cartridge. This program is a machine language monitor which allows direct access to programming the Z80 CPU. This cartridge does not require extra memory to use it, but it can take advantage of extra RAM if it is available.
"The Bally/Astrocade Game Cartridge and Hardware FAQ" says this about the MLM:
"This cartridge, which included [a 24-key keypad] overlay, provides an "easy" way to program the Astrocade in machine language. Though not a Z-80 assembler, MLM does simplify the entry of hex code (which otherwise must be entered using decimal via BASIC. Also, the keypad layout does not require the use of the key-shifts, so typing is faster). Programs can be saved via the Bally BASIC 300-baud interface (later, subroutines were written that allowed the 2000 baud version of Bally BASIC (#6004) to be swapped out for tape saving). "Machine Language Manager" does NOT have a built-in cassette interface."
This overview is part one of a four part series. The series includes:
1) Machine Language Manager, Part 1: Overview and Background 2) Machine Language Manager, Part 2: How to Use the MLM 3) Machine Language Manager, Part 3: Using MLM Example Programs 4) Machine Language Manager, Part 4: Using MLM with the Astrocade MAME Emulation
This video is split into several parts:
0:00 - MLM Titles 0:30 - Short Introduction to the MLM 3:11 - Overview with Cart, Overlay and Interface 3:32 - Close-Up of MLM and Overlay 4:38 - Closer Close-Up of MLM and Overlay 5:52 - Extreme Close-Up of MLM and Overlay 6:57 - Introduction and History of the MLM 23:25 - MLM Cart, Documentation and Overlay 24:39 - MLM Manual 26:26 - Saving/Loading at 2000-Baud 28:05 - Goldfish Demo Source Code 29:33 - Bound Astrocade Machine Language Book 33:04 - Overview of Three Z80 Programming Books 34:09 - Overview of Programming the Z80, by Rodnay Zaks 36:20 - Overview of Z80 Software Gourmet Guide and Cookbook, by Nat Wadsworth 37:46 - Overview of Software and Hardware for the Bally Arcade - A Technical Description (aka, the "Nutting Manual") 40:25 - Z80 CPU Microprocessor Instant Reference Card 41:33 - Creating a 24-Key Keypad Overlay for the MLM
45:30 - End Credits
This video is aimed at someone who has little or no understanding of Z80 machine language. A Z80 machine language programming novice, or anyone who has a passing interest in using the Machine Language Manager cartridge, will get more out of it if all of the four videos in this series are watched one after the other. Also, even if you have no plans to ever use the Machine Language Manager cartridge, anyone who wanted to know how to program the Astrocade will find plenty of general information provided in this video.